Couplings for tubes,bars and the like



Oct. 6, 1970 J. D. STUART COUPLINGS FOR TUBES, BARS AND LIKE 5 Sheets-Sheet 1 Filed Nov. 27. 1967 INVENTOR JAMES D. STUART Oct. 6, 1970 J. D. STUART 3,532,368

. COUPLINGS FOR TUBES, BARS AfiD THE LIKE Filed Nov. 2'7, 196'! 3-Sheets-Sheet 2 INVENToR JANE-sf b. 'sTvART Oct. 6, 1970 J. D. STUART 3,532,368

COUPLINGS FOR TUBES, BARS AND THE LIKE Filed Nov. 27. 1967 3 Sheets-Sheet 5 JINVENTOR' JAMES o.s'ru ART y Q1 j United States Patent "ice 3,532,368 COUPLINGS FOR TUBES, BARS AND THE LIKE James D. Stuart, Parkdale, Wolverhampton, England, assignor to Engineering Developments (Birmingham) Limited, Wolverhampton, England, a corporation of Great Britain Filed Nov. 27, 1967, Ser. No. 685,814 Claims priority, application Great Britain, Dec. 8, 1966, 54,968/66 Int. Cl. F16b 7/00 US. Cl. 287- -l 9 Claims ABSTRACT OF THE DISCLOSURE A coupling in accordance with the present invention comprises a carrier upon which any desired number of U shaped links may be mounted; each link freely embraces the carrier, a solid body fixed, or adapted to be fixed, to one end of a structral member is assembled between the free ends of the link arms, a sleeve encircles and is slidable lengthwise of the arms and a wedge which extends between the arms, carrier and sleeve, is adapted, when driven in the appropriate direction relatively to the link, to force the sleeve away from the carrier into abutment with the body and/ or structural member so that the link is tensioned and, when the structural member is assembled in a structure by couplings assembled to its opposite ends, the member is placed in compression.

This invention relates to couplings primarily intended to be used for connecting tubes, bars and analogous structural members in frameworks, particularly geodetic frameworks wherein, at each of certain positions, the adjacent ends of several such structural members are connected together so that the members extend from the position in different directions.

In accordance with the present invention, a coupling comprises a U-shaped link which embraces a carrier, a rigid body which is, or is adapted to be, fixed to one end of a structural member and is detachably assembled to and between the free ends of the link arms, a sleeve which encircles and is slidable lengthwise of the link arms, and a wedge which extends between the arms carrier and sleeve, and is adapted, when driven in the appropriate direction relatively to the link, to force the sleeve away from the carrier into abutment with the body and/ or the structural member.

In order that the invention may be understood and carried into practice more readily, reference will now be made to the accompanying drawings wherein:

FIG. 1 is a plan of a coupling constructed in accordance with one typical embodiment of the invention.

FIG. 2 is a section along the line IIII, FIG. 1.

FIG. 3 is an exploded view of certain parts of the coupling.

FIG. 4 is a section, similar to that shown in FIG. 2, of a modified coupling.

FIG. 5 is a part sectional elevation of an assembled but unlocked coupling constructed in accordance with an alternative embodiment of the invention.

FIGS. 6 and 7 are, respectively, a part sectional elevation and a part sectional plan showing the structural member of FIG. 5 in a locked condition.

FIG. 8 is a part sectional plan of a coupling constructed in accordance with another alternative embodiment of the invention, and

FIG. 9 is a section along the line IX-IX, FIG. 8,

FIG. 10 is a section along line XX, FIG. 1.

Each of the couplings shown in the drawings comprises a carrier 1 which is circular both in plan and cross 3,532,368 Patented Oct. 6, 1970 section and although, for the sake of simplicity, only one tubular structural member 2 is shown connected to the carrier, it is to be understood that, in practice, two or more structural members will be so connected at predetermined positions around and in predetermined angular relationships to the plane of the carrier.

The coupling shown in FIGS. 1-3 comprises, in addition to the carrier 1, a U-shaped link 3 having parallel arms, a sleeve 4 of which one end is spanned by a thrust plate 5 integral with the sleeve, a solid body 6, and a wedge 7.

The link embraces and projects outwardly from the carrier 2 and the internal surface of each of its arms is formed with a corresponding one of a registering pair of transverse channels 8 and of a concentric pair of armate grooves 9; the channels and grooves extending across the entire width of the respective arms and the channels are located adjacent to the free ends of the arms and on the opposite side of the grooves to the closed end of the link so as to present inwardly extending projection P thereat.

The carrier portion which is embraced by the link is also disposed betwen two shoes 10, 11 of which the adjacent faces are curved both longitudinally and transversely, the longitudinal curves being convex and concave respectively and of a smaller and larger radius respectively than the internal circumference of the carrier whereas the transverse curves are concave and concentric to and of the same radius as the cross section of the carrier so that the shoes contact the carrier in a manner which, before they are pressed and locked upon the carrier, permits the link to be turned about the latter. The shoe 10 has a groove 12 which engages the closed end of the link and the shoe 11 has a pair of grooves 13 which engage respectively with the arms of the link so that inadvertent dislodgement of the shoes from between the arms is minimised.

The link extends through and makes a sliding fit in an aperture in the pressure plate 5 so that the sleeve and plate unit is adapted to slide along the link arms; further the body 6 is a sliding fit within the sleeve and is provided with a neck 14 of which the width is greater than the width of the plate aperture, the depth does not exceed the distance between the link arms, and the length is such that transverse flanges 15 on its upper and lower faces present an enlarged head H and are able to make respective engagement with the channel 8. The body is also provided with a shank 16 which sockets into one end of, and is welded or otherwise permanently or detachably secured to, the tubular structural member 2.

The wedge 7 is inserted and driven endwise between the link arms, shoe 11 and pressure plate 5 so that the carrier is gripped between the adjacent faces of the two shoes thereby locking the link to the carrier, and the internal surface of the pressure plate is forced against the adjacent end of the flanged neck 14 thereby driving the flanges 15 against the walls of the channels 8 which are remote from the wedge, tensioning the link and if, for example, the opposite end of the structural member 2 is secured to another one of the couplings, compressing the said member axially.

After driving the wedge between the shoe and pressure plate, it is held positively against return movement by inserting a tapered pin (not shown) or equivalent expedient through a hole 17 formed in the wedge and located in a position such that the pin ends projecting beyond the opposed parallel faces of the wedge overhang and contact the arm edges remote from the wider end of the wedge. Further, by removing the pin or analogous expedient from the hole 7 and inserting it in an identical hole 18 adjacent to the thinner end of the wedge, the latter is prevented from falling or being removed from the link when driven in the reverse direction to unlock the link from the carrier.

When once the body 6 is secured to the structure member 2, the said member is connected to the carrier by the following sequence of operations, namely: first the shoe is inserted between the link arms and engaged with the closed end of the link; secondly, the carrier is embraced by the said arms until the curved face of the shoe 10 contacts the carrier; thirdly, the shoe 11 is inserted between and slid lengthwise of the arms until its curved face also contacts the carrier; fourthly, the sleeve and pressure plate unit 4, 5 is passed on to and slid along the arms until the channels 8 are located beyond the sleeve end remote from the pressure plate; fifthly, the flanges are engaged with the channels 8 and the unit 4, 5 is slid along the arms in the reverse direction until the sleeve surrounds the body 6 and therefore prevents endwise movement of the flanges in the channels; sixthly, the coupling is moved along and/or swung around the carrier until it is located at a pre-determined position and in a pre-determined angular relationship thereto, whereupon the Wedge is inserted and driven home between the link arms, shoe 11 and pressure plate to lock the link to the carrier.

The carrier may be of any desired construction, shape and/or cross section other than as shown in FIGS. l3; for example, it may consist of a single ring or loop which, instead of being circular in shape and cross section, is circular in shape but polygonal in cross section, or is polygonal in shape and circular or polygonal in cross section; alternatively it may consist of two or more of the rings or loops permanently fixed together in different intersecting planes, a rod which is straight or arched along its length and has a stop on each end, or two or more of such rods permanently fixed together in any predetermined angular relationship.

Also the shape and/or or dimensions of the solid body 6 may be modified to enable it be secured to a structural member of different cross sectional shape and/or dimensions from the member 2, and in certain circumstances (for example when a tubular member of which the internal cross section is identical to the cross section of the body, is secured to the latter) the arrangement may be such that, as the coupling is locked to the carrier, the end of the member may be abutted by the rim of the sleeve instead of, in addition to, the keyed neck being abutted by the pressure plate.

In the coupling shown in FIG. 4, the link 3 is assembled to carrier 1a which is square in cross-section, the structural member connected to the carrier by the coupling consists of a T-section 'bar 2a, a shoe 11a is interposed only between the carrier and wedge 7, the end of the solid body 6 remote from the neck 14 has a transverse slot in which the stem of the bar engages and is secured in spaced relationship to the head of the bar, and the sleeve is formed with a registering pair of slots which slidably engage the said stern as the sleeve and plate unit 4, 5 is driven away from and the link is locked upon, the carrier by the wedge.

The presence of the arcuate grooves 9 in the adjacent faces of the link arms enables the link 3 to be moved into and locked in a different angular relationship to the carrier 1a without completely dismantling the coupling; this result may be obtained by unlocking the coupling, removing the wedge from between the link arms, sliding the link lengthwise of the carrier until the latter is disposed between the grooves, whereupon, having turned the link around the carrier through 90, or a multiple thereof, the procedure may be reversed to relock the coupling.

In the coupling shown in FIG. 5-7, the solid body 6a has a dovetail shaped neck 14a and the internal faces of the free ends of the link arms are so relatively inclined as to form an open-ended pocket in which the neck makes a free sliding fit until, when the wedge 7a is driven home,

the neck is forced against the said inclined faces as the sleeve 4a is forced against the solid body.

The narrower end of the wedge is provided with a stem which is offset from the longitudinal centre line of the wedge and has, at its free end, a head 7c of such dimensions that it is unable to pass through the space between the link arms; hence, when the coupling is unlocked, the wedge is retained in the assembly but, when turned through about its lingitudinal centre line to the position shown in dotted lines in FIG. 5, the sleeve may be moved toward the closed end of the link to permit the neck 14a to be disengaged from, or engaged with, the open-ended pocket.

The coupling shown in FIGS. 8 and 9 differs from the coupling shown in FIGS. 57 mainly in that the wedge 7d has a longitudinal bore through which the stern of a bolt 21 extends and is engaged by a nut 22 located and held against rotation within a transverse aperture 7 in the wedge. The bolt is suspended in a saddle 23 traversing the narrower end of the wedge and seating upon the arms of the link 3 so that, upon rotating the bolt in the appropriate direction, the wedge is drawn towards the saddle by the nut to lock the coupling. Having locked the coupling, rotation of the bolt in the reverse direction is prevented by a locking washer 24 which is trapped between the bolt head and the saddle and of which the opposite ends are bent, respectively, into contact with a face of the bolt head and one side of the saddle. The length of the bolt shank is such that, as and when it is rotated in the reverse direction after straightening the washer 24, the wedge may be forced from between the link arms by the nut to a position wherein, whilst the shank is still engaging the nut, the sleeve 4a may be slid clear of the body neck 14a to permit disengagement of the neck from between the link arms.

I claim:

1. A coupling for connecting tubes, bars and like structural members to a carrier, comprising a U-shaped link adapted to embrace the carrier, a rigid body which is adapted to be fixed to one end of the structural member and is detachably assembled to and between the free ends of the link arms, a sleeve which encircles and is slidable lengthwise of the link arms, and a wedge which extends between the arms, carrier and sleeve and is adapted, when driven in the appropriate direction relatively to the link, to force the sleeve away from the carrier, and stop means for limiting axial movement of the sleeve away from the carrier to tension said arms between their detachable connection to said body and the carrier.

2. A coupling as claimed in claim 1 wherein the body is provided with a neck which is a sliding fit within recesses in the free ends of the adjacent faces of the link arms and is forced against the walls of the recesses remote from the carrier as the sleeve is forced away from the carrier against said stop means.

3. A coupling as claimed in claim 1 wherein the sleeve end adjacent to the carrier is provided with and is spanned by, a pressure plate having an aperture through which the link extends and makes a sliding fit.

4. A coupling as claimed in claim 2 wherein the neck is forced against the recess Walls by abutment of the wedge with the free end of the neck.

5. A coupling as claimed in claim 2 wherein each of two opposed faces of the body neck is provided with a transverse flange which engages with a channel formed in a corresponding one of the adjacent faces of the link arms.

6. A coupling as claimed in claim 2 wherein the body neck is of dovetail shape and engages an open-ended pocket of complementary shape formed between the link arms by the recesses in the adjacent faces of the arms.

7. A coupling as claimed in claim 1 wherein the wedge is provided with means whereby its complete removal from between the link arms is prevented.

5 8. In combination with a carrier member and an elongate structural member which is fixed at one end thereof, a coupling device for securing the other end of said structural member to said carrier member while subjecting the structural member to axial compression, said coupling device comprising:

a U-shaped link having a pair of spaced arms straddling said carrier member and projecting therefrom toward said other end of the structural member,

a rigid body secured to said other end of the structural member and having a free end portion received between the free ends of said arms,

means for limiting relative axial extension of said body with respect to said link,

a sleeve surrounding said arms and axially slidable thereon to encompass the free ends thereof, the length of said sleeve being such as to expose the space between said arms between it and said carrier,

a wedge received within said exposed space between said arms to force said sleeve axially away from said carrier, and

stop means acting between said sleeve and said other end of the structural member to engage said projections forcibly against said enlarged head.

9. The assembly as defined in claim 8 wherein said sleeve is provided with a pressure plate at that end facing said carrier, said body being Wider than said arms and said pressure plate having an opening therein commensurate with the width of said arms whereby interengagement between said pressure plate and said body efiects said stop means.

References Cited UNITED STATES PATENTS 1,084,379 1/1914 Wile. 3,164,914 1/1965 Wilson 2871l4 XR 2,744,717 5/ 1956 Heusner.

DAVID J. WILLIAMOWSKY, Primary Examiner A. V. KUNDRAT, Assistant Examiner US. Cl. X.R. 24-73 

